Nowadays, many optical-electro technologies are rapidly developed and used in next generation of Flat Plate Displays (FPDs) such as Projection Display, Flexible Display and so on. Under the above-mentioned development tendency, a kind of display based on electro-wetting principle is broadly concerned due to its excellent display characteristic just like fast response, wide viewing-angle, and low power-consumption.
Referring to FIG. 12, a side, cross-sectional view of parts of a conventional EWD device 10 under a dark condition is shown. The EWD device 10 includes a first substrate 11, a second substrate 18 opposite to the first substrate 11, a first liquid 13 and a second liquid 12 both provided between the substrates 11, 12, a hydrophobic insulating film 15, a plurality of pixel walls 16, and an active matrix layer 17 disposed on the second substrate 18. The active matrix layer 17 includes a plurality of pixel electrodes 14 and a plurality of TFTs (not shown). The pixel electrodes 14 are arranged in matrix on the second substrate 18, and respectively connected to the TFTs. The hydrophobic insulating film 15 covers the active matrix layer 17. The pixel walls 16 are disposed on the hydrophobic insulating film 15 in a latticed form. Each minimum area surrounded by the pixel walls 16 is defined as a pixel area R, which is located correspondingly to the pixel electrode 14. The first liquid 13 is located between the adjacent pixel walls 16. The material of the first liquid 13 is an opaque oil, such as colored Alkane, Hexadecane or the like. The second liquid 12 is immiscible with the first liquid 13, and filled between the first substrate 11 and the first liquid 13. The material of the second liquid 12 is transparent conductive liquid, such as water, salting liquid, and a solution mixed with Ethyl Alcohol and potassium chloride solution.
When a voltage less than a threshold voltage is applied between the second liquid 12 and pixel electrode 14, the second liquid 12 overlaps with the first liquid 13, and the first liquid 13 smoothly covers the hydrophobic insulating film 15. Incident light is absorbed by the first liquid 13, so that the pixel area R of the EWD device 10 displays a dark condition.
Also referring to FIG. 13, a side, cross-sectional view of parts of the EWD device 10 under a bright condition is shown. When a voltage greater than the threshold voltage is applied, the surface tension of the second liquid 12 is changed. The second liquid 12 pushes the first liquid 13 towards one of the pixel wall 16. Incident light can pass through the second liquid 12, so that the pixel area R of the EWD device 10 displays a bright condition.
However, because touch control technology is widely used, more and more consumers require electronic information devices, just like cell phone, PDA, and ATM, to be installed the touch control function so as to enhancing the interaction between consumer and electronic information devices. But the conventional EWD devices does not have the touch control function yet.
It is, therefore, needed to provide an EWD device that can overcome the above-described deficiencies.